Simalar problem on my 58 inch it was the transformer.ran me three hundred at tv clinc parts a labor
The P52937 uses the PTK195 series chassis. If the TV makes a squeeling noise the instant it is plugged in then unplug it immediately and do not plug it back in. I have seen this many, many times. The flyback (high voltage) transformer has shorted out and the extra current it was drawing has shorted out the horizontal output transistor, so the B+ supply is dead shorted and the power supply squeels as a result. This is very common in that chassis. The flyback and output transistor will have to be replaced by someone with experience in RCA projection TV's. The HV block in the PTK169 sets is the one known to be bad a lot - the block in the 195 is very reliable and I have never seen one of those bad.
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